[TIB] Re: Graphics

To: ti-basic@lists.ticalc.org
Subject: [TIB] Re: Graphics
From: "Arthur J. O'Dwyer" <ajo@andrew.cmu.edu>
Date: Wed, 4 Jun 2003 21:28:06 -0400 (EDT)
In-Reply-To: <20030604220247.56CA418221@mx-1.sollentuna.net>
References: <20030604220247.56CA418221@mx-1.sollentuna.net>
Reply-To: ti-basic@lists.ticalc.org

On Thu, 5 Jun 2003, Ecartis wrote:
> > From: "RaptorDrew" <raptordrew@covad.net>
> >
> > Two questions - (both for the 83+/SE)
> >     First, is there a way to make checkerboard designs on the graph
> > screen easily, besides using diagonal lines?
>
> Not as far as I know, assuming you mean single-pixel-wide checkerboard
> squares ("gray" of a sort).  You might investigate the flood-fill designs
> that the '83+ can put above and below Y= equations on the graph; you
> might be able to get a 2x2-square checkered pattern out of them.

As it turns out, the lines in the diagonal flood-fill pattern are just
a bit too far apart (3 pixels) to give any useful checkerboard pattern
when overlapped.  What a pity.

On the other hand, you may find that using the Text( command to write
directly to the screen works faster than the Line( command (which has
to convert points to pixels first).  The following program prints a
small patch of checkerboard to the screen:

  12->J: 6->K
  ClrDraw
  For(A,1,J-1
    For(B,1,K-1
      Text(45-2B,10+2A,"x"
    End
    Text(43-2B,10+2A,"   "
  End

where "x" represents the "mean of x" character found in the TI-83's
VARS-Statistics... menu.  IIRC, on the '83+ you can use the lowercase
'x' character directly.

The lowercase 'w' works even better than the 'x', but I just realized
that and don't feel like reworking the program to take advantage of
it.

HTH,
-Arthur

Follow-Ups:

[TIB] Re: Graphics

From: robvanwijk@gmx.net